Patch is attached which generates a DeprecationWarning for the use of `backticks` if the -3 argument is passed on the command line:

tom@localhost:~/src/python-trunk$ ./python -3
warning: callable() not supported in 3.x
warning: callable() not supported in 3.x
warning: callable() not supported in 3.x
warning: callable() not supported in 3.x
warning: callable() not supported in 3.x
warning: callable() not supported in 3.x
warning: callable() not supported in 3.x
warning: callable() not supported in 3.x
Python 2.6a0 (trunk:56394M, Jul 15 2007, 20:54:01) 
[GCC 4.1.2 (Ubuntu 4.1.2-0ubuntu4)] on linux2
Type "help", "copyright", "credits" or "license" for more information.
>>> `1`
sys:1: DeprecationWarning: backquote not supported in 3.x
'1'
>>>